Advances in research have led to new drugs that stimulate the body’s immune system to better fight cancer. There are various types of immunotherapy drugs currently used to treat melanoma, including immune checkpoint inhibitors and interleukin-2.

Immune Checkpoint Inhibitors

T-cells are white blood cells that fight infection and cancer cells. In order to keep T-cells from also attacking the body’s own healthy cells, the body’s immune system uses “checkpoints,” which are proteins that inhibit T-cells.

In cases of advanced skin cancer or metastatic melanoma, a treatment called Checkpoint Blockade Immunotherapy is given to silence these checkpoints, thereby releasing a flood of T-cells against the cancer cells.

The following types of checkpoint blockade therapies are currently given to patients with metastatic melanoma:

• Cytotoxic T-lymphocyte Antigen-4 blockers, such as Ipilimumab (Yervoy): These drugs work by blocking the CTLA-4 protein that normally helps regulate T-cells.
• PD-1 blockers, such as Nivolumab (Opdivo) and Pembrolizumab (Keytruda): These drugs work by blocking the PD-1 protein that also helps regulate T-cells.

Interleukin-2 (IL-2)

Interleukins are proteins that are naturally produced in the body to boost the overall immune system. A synthetic form of interleukin-2 (IL-2) may be used to treat metastatic melanomas, as well as earlier stage melanomas. Frequently given as intravenous infusions, IL-2 therapy could potentially be administered as injections by some patients at home.

In cases of metastatic melanoma, IL-2 therapy may shrink an advanced melanoma tumor. In cases of earlier stage melanoma, IL-2 therapy may be injected directly into a tumor to lessen the risk of recurrence.

Side Effects of Immunotherapy for Metastatic Melanoma

It is important for you to discuss side effects with your doctor, and report any new side effects after treatment has begun.

The side effects of CTLA-4 inhibitors most commonly include:

• Diarrhea
• Fatigue
• Itching
• Skin rash

Side effects of PD-1 inhibitors may include:

• Cough
• Fatigue
• Nausea
• Skin rash
• Itching
• Constipation
• Diarrhea
• Loss of appetite
• Joint pain

Side effects of IL-2 therapy may include the following. These effects tend to be milder for earlier stage melanomas when IL-2 is injected directly into a tumor.  

• Chills
• Fever
• Aches
• Fatigue
• Low blood cell counts